Camera



Feb.22,1944.

c. B. GATY 2,342,513

CAMERA Original Filed Nov. 19, 1941 Tamil.

INVENTOR A I T Z NEYS Patented Feb. 22, 1944 CAMERA Clinton B. Gaty.Alexandria, Va assignor to Fairchild Aviation Corporation, Jamaica, N.Y., a corporation of Delaware Original application November 19, 1941,Serial No. 419,684, now Patent No. 2,325,313, dated July 27, 1948.Divided and this application September 16, 1942, Serial No. 458,506

3Clalms.

This invention relates to a lens heating device and to an electricalconnection therefor for a motion" picture camera adapted to photographthe results of actual or simulated aerial machine The complexity andamount of equipment, instruments, controls, etc., installed in thecockpit of a modem military airplane, particularly an airplane of thefighter or interceptor type, so crowds the cockpit that there is butlittle space therein other than what is essential for the as thealtitude, and accordingly the temperature at which the camera operatesundegoes frequent pilot's activities. This is particularly true in thosetypes of fighter airplanes carrying rigidly mounted wing guns which aretrained on the target by pointing the airplane in accordance with theposition of the target, as viewed in a gun sight mounted in the cockpit.Accordingly, such equipment or instruments, other than those absolutelynecessary, and proposed for installation in the cockpit, must ofnecessity be as small aziid as light as is consonant with efilcientopera on.

It is often desirable to eq ip modern military aircraft of the abovetype with motion picture cameras of the nature described in thecopending application of Gaty et al., Serial No. 395,098, filed May 24,1941. These cameras are, in certain instances, mounted in the cockpitadjacent the gun sight in a position to photograph the viewing plate ofthe gun sight, and in other instances are attached directly to the winggun. In each instance there is so little space for the camera that itand its attachments must be as small as possible.

A camera of this sort is, of course, subjected to severe usage by reasonof vibration, weather conditions and low temperatures at the substan- Itial altitudes at which it operates. Thus, the space limitations of thecockpit or airplane wings,

which necessitate crowding the operating mechsary, in proper operativecondition so as to obtain and substantial changes, it is important toutilize fully the heating capacity of the heater. This factorcomplicates the mounting of the heater and the electrical connectionthereof with the source of current.

Accordingly it is among the objects of this invention to provide a lensheating device and electrical connection therefor capable among otherthings of keeping the lens in proper operative condition, and yet be ofsuch nature as to occupy a minimum amount of space and withstand allshocks and vibration to which it may be subjected. Other objects will bein part apparent and in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts as will beexemplified in the structure to be hereinafter described, and thescopeof the application of which will be indicated in the followingclaims.

This application is a division of the copending application of ClintonB. Gaty, entitled "Camera lens heating device," Serial No. 419,684,filed November 19, 1941, issued July 27, 1943, as Patent In the drawing:

Figure 1 is a full scale elevation of a motion picture camera on whichmy lens heating device and electrical connection therefor is mounted,certain portions being shown in section, and a portion of the camerabeing broken away to show more clearly a portion of the electricalconnection;

Figure 2 is an enlarged fragmentary sectional elevation of a portion ofthe electrical connection shown in Figure 1; and,

Figure 3 is a fragmentary side elevation of my lens heating devicemounted on a lens system of a type different from that shown in Figure1.

Similar reference characters refer to similar parts throughout thevarious 'views of the drawing.

In Figure 1, I have generally indicated at Ill a motion picture camerawhich in most respects is substantially identical to that shown anddescribed in detail in the copending application of Gaty et al., SerialNo. 395,098, filed May 24, 1941, mentioned above. The camera includes atop plate H which may be secured in any suitable manner to the casingl2, and has secured thereto as by bolts l3 a lens support generallyindicated at It within which the camera lens (not shown) is mounted. Afilter support, generally indicated at I I is detachably secured to lenssupport II as by screws l8, and on support II is detachably mounted afilter and heater assembly generally indicated at H which iselectrically connected, as will be described hereinbelow, to a condu t rceptacle or electric plug socket generally indicated at it.

Lens support Mi includes a generally flat base is through which bolts l3extend to secure the lens support to camera top plate ii. Extendingupwardly from base is is a tubular housing which is widened at its topto provide a generally cylindrical casing 2i flanged as at 22. Casing isapertured as at 23 to provide access to the usual diaphragm adjustingrings 28. It will now appear that the camera lens and the diaphragmadjusting mechanism is partially enclosed, and

accordingly partially protected by lens support it, In other words, thecamera lens and the diaphragm mechanism are disposed in a space, thetemperature of which, as will appear below, can be controlled to acertain extent to maintain the lens and diaphragm in proper operativecondition.

Filter support it includes a flange 25 which is secured to flange 22 oilens support M by screws it. Extending upwardly from flange 25 is acylinder 29, the upper end of which is reduced and threaded as at 211,and it is on this threaded portion oi. the filter support that filterandheater assembly ll is detachably mounted. it might be noted at thispoint that filter support l5 provides a continuation 01' what is' ineffect a duct formed by lens support it.

The filter and heater assembly 97 comprises a more or'less tubularmember generally indlcated at 28 comprising a cylindrical portion 29 anda frusto-conical portion 30 havingvan outwardly extending annular flange38. A shoulder 32 is formed within member 28 to provide a seat for afilter 33 which may be held in proper position by a snap ring 34 adaptedto snap into a small groove provided therefor, and rest against the edgeof the outer surface of the filter. Cylindrical portion 29 of the member28 is also provided with an annular fiange 35 from which extends aninteriorly threaded portion 2% by which the assembly H is detachablymounted on filter support 55. A frusto-conical band is? is disposedabout the member, 28 so as to form therewith a space 38. Band 87 engagesflanges 3i and 35. and is held in assembly with the member 28 againstthese flanges by a retaining ring 39 which may be secured to flange 35in any suitable manner. Within the space 38 formed by band 37 and member28 is a heater coil Mi formed by a length of insulated wire, the ends 4!and 42 of which extend through suitable holes formed in band 31. andhave attached thereto respectively jacks l3 and 44 which may beconnected to socket l8, as will be described.

It may now be seen that the filter and heater unit I1 is seli-containedand readily attachable to or detachable from filter support l5.Furthermore, cylindrical portion 29 of the assembly I! provides afurther elongation of the duct formed by lens support l4 and filtersupport l5, and the space within this duct between filter 33 and thecamera lens, which is disposed adjacent the joint between flanges 22 and25 of the lens and filter supports l4 and I5, respectively, issubstantially a dead air space. Thus, when heater coil is energized,this dead air space is heated, and also the metal portions or assemblyI! are heated,

resulting in heating of filter 33 by both convection and conduction.Furthermore, as member 28 of the heater and filter assembly I! isdirectly connected to filter support II, and as the filter supportdirectly engages lens support I4, these metal parts are all heated uponenergization of the heater, as well as the air space enclosed thereby.the camera lens, which is disposed adjacent the top of the lens mount,is also heated both by convection and conduction. Inasmuch "as the metalparts are good conductors of heat, and also are capable of retainingheat for a reasonable period oi time, the lens and filter are maintainedsufllciently warm, regardless of abrupt variations in altitude,and-accordingly temperature.

As noted hereinabove, camera ill is, during its operation, subject tosubstantial shock, and even when not operating is subject to substantialshock from gun recoil and substantial vibration from the airplane. Underthese conditions, I have found that to attach the ends Or leads 4! and82 of heater 3b to a conventional plug is unsatisfactory, as the plug,by reason or its relatively substantial inertia, is apt to ,work loosefrom the receptacle or socket into which its conductors extend. Also,because of the substantial current, which may be as high as 10 amperes,necessary to energize heater to, the conductors of such a conventionalplug would have to be of such a size that there would be insufilcientroom on top plate ill of the camera on which to mount such a plug. 1!,accordingly, have provided iacks t3 and 8t and socket is for thereception thereof, which will now be described.

As more clearly shown in Figure 2, top plate M is drilled as at and 46to provide a pair of holes for the reception of Jacks t3 and t4 intosocket is. Socket it comprises a pair of casings ti and t8, and as theseare identical, casing 41 only will be described. Thus, casing 6?, whichis preferably formed from a suitable dielectric material, is so moldedas to provide a pair of chambers 49 and 5b, which are parallel, andextend throughout the casing. Adjacent the upper end oi chamber 69, thecasing is shouldered as at 58 and 52, forming a reduced portion 53 whichextends into hole 55 in camera top ll, being restrained from projectingpast the top surface of top ill by shoulder 5i. A similar proiection 56is formed adjacent the upper end of chamber 50, and this projectionextends into hole 66. Chamber 5B is also provided with a shoulder 55,similar to shoulder 52. Chambers 89 and 50, respectively, receive theupper or female ends of conductors 56 and 51, into which the reducedendsllSa and a of jacks 43 and d4 extend when the jacks are connected tosocket l8. It may now be seen that conductors 56 and 51 are not onlyinsulated from one another by casing 41, but are also amply insulated,as are jacks 43 and H, from camera top H by projections 53 and 54 of thecasing.

Casing 48 is provided with channels similar to the channels in casing 41and these latter channels receive the lower or male ends 01' conductors56 and 51, these male ends 56a and 56b extending from the bottom ofcasing 48, and being insulated from one another as in'the case of thefemale ends of the conductors. Male ends 56a and 56b (Figure 1) may beattached to suitable leads within the camera, which are connected to themain plug receptacle of the camera (not shown) but preferably these maleends are connected in series with a thermostat (not shown) mountedwithin camera casing l2, which automatically completes the circuit toheater 40 at a predetermined temperature.

Referring back to Figure 2, casings 41 and 4B are provided with coaxialcentrally disposed bores in which is disposed an eyelet 58, the oppositeends 58a and 58b of which are riveted or spun over to engagerespectively shoulders 59 and 60, formed at the bottoms of recesses GIand 62, respectively, in casings 41 and 48. Eyelet 58 thus holds the twocasings together and furthermore provides a hole for the reception of ascrew 63, which extends through top plate II and has threaded on thelower end thereof a nut 64 which when taken up on the screw holds socketl8 securely against the underside of top H. Preferably top H iscountersunk to receive the head 65 of screw 63 so that the top of thescrew is flush with the surface of top plate II. It will now appear thatsocket I8 is firmly secured to the camera top plate II in such a manneras to preclude its working loose by reason of gun recoil or planevibration. Furthermore, the conducting portions of the socket, as wellas jacks 43- and 44, are completely insulated from top plate II, as wellas from one another, and in spite of the small size of the socket (seeFigure l) are well able to carry the substantial current necessary toenergize heater 40. Furthermore, by reason of the small size of socketl8 it may be disposed within the camera where there is no danger of itsbeing broken or knocked loose, and in spite of its small size, itisquite capable of receiving jacks 43 and 44 which, because of theirrelatively slight weight, have insuificient inertia to cause theirworking loose from recoil shock or airplane vibration.

When camera I II is installed in the cockpit adjacent a gun sight of thetype shown in the copending application of Gaty et 9.1., Serial No.395,098, filed May 24, 1941, it is usually necessary to secure to lensmount l4 (Figure 3) an erecting system which I have here generallyindicated at 88. By means oi this erecting system, the optical axis ofthe camera lens-may be disposed at an angle to the viewing axis, 1. e.,the axis of heater and filter assembly H. In this case, assembly I1 ismounted directly on the erecting system 66 which, accordingly, inaddition to its designed function, functions somewhat in the manneroutlined above with respect to filter support II (Figure l) In otherwords, the assembly H, the erecting system 46, and the lens support l4,provide conduction and convection paths il'or the fiow of heat from theheater in assembly It may now be seen that I have provided a lensheating device and an electrical connection therefor which attains theseveral objects set forth hereinabove in a thoroughly practical andemcient manner.

As many possible embodiments may be made of the above invention, and asmany changes might be made in the embodiment above set forth, it is tobe understood that all matter hereinbefore set forth, or shown in theaccompanying drawing, is to be interpreted as illustrative and not in alimiting sense.

, port, a filter mounted in said member, said memher having an annularchamber therein, a coil of wire comprising a heater mounted in saidchamber for heating said filter by conduction and said lens byconduction and convection, an electric plug receiving device mountedwithin said camera, and means forming an electrical connection betweensaid device and said heater.

2. The combination with a small motion pic ture camera of a type adaptedto be attached to an airplane of a lens mounted on said camera, atube-like support surrounding said lens and extending a substantialdistance from said camera, means for securing said support to saidcamera, an optical element carrying member detachably mounted on theouter end of said support, an optical element mounted in said member,said member having an annular chamber therein, a coil of wire comprisinga heater mounted in said chamber for heating said lens and said opticalelement by conduction and convection, an electric plug receiving devicemounted within said camera, and means forming an electrical connectionbetween said device and said heater.

3. The combination with a small motion picture camera of a type adaptedto be attached to a'military airplane for photographing th effects ofmachine gun or cannon fire, of a lens mounted on said camera, atube-like support surrounding said lens and extending a substantialdistance from said camera, means for securing said support to saidcamera, afilter carrying member detachably mounted on the outer end ofsaid support, a filter mounted in said member, said member having anannular chamber therein, a coil of wire comprising a heater mounted insaid chamber for heating said filter by conduction and said lens byconduction and convection, an electric plug receiving device mountedwithin said camera, a pair of elongated fiexible leads connected to saidcoil and extending therefrom externally of said tube-like support, and apin Jack secured to each of said leads for insertion in said plugreceiving device to form .a connection between said device and saidcoil.

CLINTON B. GA'I'Y.

